| ABN Construction Limited | Construction | 2018 |
| ABN Investment & Estate Limited | Real estate | 2022 |
| ABO Energy Consulting Ltd | Professional & scientific | 2024 |
| Aboalkaz Ltd | Information & communication | 2020 |
| Abodan Limited | Wholesale & retail | 2024 |
| Abode (LMH) Limited | Construction | 2018 |
| Abode Group Holdings Ltd | Financial services | 2020 |
| Abode Homes (Forest View) Limited | Construction | 2023 |
| Abode Homes (Horley) Ltd | Professional & scientific | 2020 |
| Abode Homes (Southborough) Ltd | Real estate | 2020 |
| Abode RGS Ltd | Hospitality | 2023 |
| Abodetech Limited | Wholesale & retail | 2020 |
| Abodia Group Ltd | Professional & scientific | 2016 |
| Abokayedshop Ltd | Wholesale & retail | 2024 |
| Abondance LES Milles Merveilles Limited | Wholesale & retail | 2025 |
| Abood Trade Limited | Wholesale & retail | 2025 |
| About Lending Limited | Financial services | 2021 |
| About Lending SPV1 Limited | Financial services | 2021 |
| About Premium Content (UK) Limited | Information & communication | 2020 |
| Above Average Official Limited | Wholesale & retail | 2025 |
| Above Beyond Automotive Limited | Wholesale & retail | 2020 |
| Above Beyond Finance Limited | Wholesale & retail | 2023 |
| ABP Healthcare Limited | Health & social care | 2025 |
| ABP Ventures Limited | Real estate | 2025 |
| ABR Automotive Solutions Ltd | Wholesale & retail | 2025 |
| Abram a Ltd | Transport & logistics | 2017 |
| Abram Partnership Ltd | Financial services | 2009 |
| Abramelin Consulting Ltd | Financial services | 2016 |
| Abran Ltd | Wholesale & retail | 2023 |
| Abrar Enterprises Ltd | Wholesale & retail | 2025 |
| ABS Global Construction Ltd | Construction | 2026 |
| ABS Solutions Ltd | Construction | 2024 |
| Absire Studio Ltd | Professional & scientific | 2019 |
| Absolut Signs Ltd | Construction | 2002 |
| Absolute Access Scaffolding Ltd | Construction | 2011 |
| Absolute Advertising PC | | 2017 |
| Absolute Efficiency Limited | Professional & scientific | 2016 |
| Absolute Groundworks NE Ltd | Construction | 2018 |
| Absolute Performance Ltd | Arts & recreation | 2008 |
| Absolute Signs and Graphics Ltd | Manufacturing | 2012 |
| Absolute Technology Portfolios Ltd | Information & communication | 2006 |
| Absolute Traders Ltd | Wholesale & retail | 2021 |
| Absolute Waste Ltd | Water & waste | 2025 |
| Absolutely NO Nonsense Admin Ltd | Information & communication | 2016 |
| Absorb Online Learning Limited | Education | 2015 |
| Absorise Digital Limited | Professional & scientific | 2017 |
| Abstract Works Ltd. | Information & communication | 2017 |
| Abstragan Holding Limited | Wholesale & retail | 2011 |
| ABT L2 Limited | Administrative & support | 2026 |
| ABT L5 Ltd | Administrative & support | 2026 |
| ABT Property Refurbishments Ltd | Construction | 2026 |
| ABT Staff Solution UK Ltd | Administrative & support | 2026 |
| Abtb Newco Ltd | Professional & scientific | 2020 |
| ABU Sufyan Trader Ltd | Wholesale & retail | 2024 |
| Abuela Holdings Limited | Financial services | 2021 |
| Abundle Ltd | Wholesale & retail | 2024 |
| ABX Group Limited | Real estate | 2025 |
| Abyo Software Ltd | Information & communication | 2025 |
| ABZ Alpha Ltd | Financial services | 2023 |
| Abzenorail Limited | Construction | 2020 |
| AC Accounting and Consulting Limited | Professional & scientific | 2021 |
| AC Care Services Limited | Health & social care | 2015 |
| AC Contracting & Tutoring Limited | Professional & scientific | 2019 |
| AC Doors Wales Ltd | Administrative & support | 2024 |
| AC Entertainment Electrical Limited | Construction | 2017 |
| AC Geotechnical Engineer Ltd | Administrative & support | 2019 |
| AC Parl Street Management Limited | Real estate | 2018 |
| AC Quantity Surveying and Estimating Services Ltd | Professional & scientific | 2015 |
| AC Residential Ltd | Real estate | 2014 |
| AC Struthers Limited | Construction | 2016 |
| AC Ventilation Solutions Ltd | Construction | 2012 |
| Ac-Dc Food Limited | Hospitality | 2018 |
| AC777 Ltd | Construction | 2018 |
| ACA Lucinet Limited | Extraterritorial | 2025 |
| ACA Marketing Ltd | Professional & scientific | 2025 |
| ACA Tech Limited | Information & communication | 2025 |
| Academi Berfformio Caerdydd CYF | Arts & recreation | 2013 |
| Academic Advantage Ltd | Education | 2023 |
| Academic Ants Ltd | Public administration | 2025 |
| Academy 3 Limited | Other services | 2018 |
| Academy Class Group Ltd | Other services | 2018 |
| Academy of Applied Learning Ltd | Information & communication | 2019 |
| Academy of Counselling Studies Ltd | Education | 2024 |
| Academy of Solar Excellence Ltd | Construction | 2020 |
| Acalypha Security Limited | Wholesale & retail | 2025 |
| Acanatan Ltd | Transport & logistics | 2025 |
| Acapela Publishing Limited | Information & communication | 2013 |
| Acar Engineering Limited | Professional & scientific | 2011 |
| ACB QA Ltd | Financial services | 2025 |
| Acbs Ltd | Wholesale & retail | 2024 |
| ACC Drivers Center Ltd | Administrative & support | 2018 |
| ACC Trans Ltd | Transport & logistics | 2019 |
| Accela Imports Ltd | Wholesale & retail | 2019 |
| Accelerate Freight Limited | Transport & logistics | 2008 |
| Accelerate MRS Ltd | Information & communication | 2012 |
| Accelsiors CRO and Consultancy Services (UK) Limited | Professional & scientific | 2015 |
| Accendo Care Ltd | Professional & scientific | 2015 |
| Accent Retail Group Ltd | Wholesale & retail | 2019 |
| Accentric Limited | Real estate | 2001 |
| Acceptivo Technologies UK Limited | Information & communication | 2021 |